Yellowback Fusilier

Caesio xanthonota is a pelagic marine fish belonging to the family Caesionidae. It is native to the tropical Indo-Pacific, being found in shallow water from the African coast to Indonesia.

Description

The yellowback fusilier is a small to medium-sized fish which grows to about 40 cm (16 in) long. The mouth is small and terminal and is protusible, being able to be extended forward to swallow food. The body is fusiform or spindle-shaped. The dorsal fin has 10 spines and 14-15 soft rays. The anal fin has three spines and 11 or 12 soft rays. The caudal fin is deeply forked.

The body coloration is greyish blue with a bright yellow zone on the back. The yellow area goes from the forehead, between the eyes, to the tail, and includes the dorsal fin and the caudal fin. This area corresponds more or less to the upper third of the body. The belly is plain white.

Distribution and habitat

Caesio xanthonota is widely distributed throughout the tropical waters of the Indian Ocean, the Red Sea and Persian Gulf excluded, to Indonesia in the western Pacific Ocean. It lives in mid-water in deep lagoons and close to external reefs from the surfaceto 50 m deep.

Diet

It feeds on zooplankton, so it is a planktivore.

Behaviour

The yellowback fusilier is diurnal, and lives in groups and forms schools with other caesionids such as Caesio teres. Often, confusion between these two species occurs, thus Caesio teres has a variable yellow zone which changes with the age. This yellow zone starts from the anterior part of the dorsal fin and draws a diagonal to the low part of the caudal peduncle.